This invention relates to a navigation system in which an optimum path from a start point to a destination is calculated, and the vehicle is guided along the optimum path.
Generally, in a navigation system of this type, an optimum path between a start point and a destination is calculated beforehand in accordance with a map information, and after the start of a vehicle, path information, such as road names and the direction of travel, are sequentially displayed in the form of a picture image on a display device in accordance with the present position of the vehicle, thereby guiding the vehicle from the start point to the destination.
In such a navigation system, the path information is sequentially displayed, and therefore even if the driver has no idea of the path from the start point to the destination, he can arrive at the destination without fail by driving the vehicle in accordance with the path information displayed.
When driving the vehicle, it is desirable for the driver to know the optimal path beforehand, for example, in order to secure driving safety and to prevent the vehicle from departing from the optimal path, which may be caused by the overlooking the displayed path information.
In the above conventional navigation system, however, the path information is sequentially displayed in accordance with the present position of the vehicle, and therefore the path information is not displayed unless the vehicle is actually driven. Thus, the conventional navigation system does not allow the driver to know the optimal path beforehand.